<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <title>Flex Layout Demo</title>
  <style>
    .parent {
      display: flex;
      width: 600px;
      height: 600px;
      background: gray;
    }
    .child {
      width: 100px;
      height: 100px;
    }
    /* 剩余空间被分为 3 份，c1 占 1/3，c2 占 2/3 */
    .c1 {
      flex: 1;
      background: skyblue;
    }
    .c2 {
      flex: 2;
      background: green;
    }
    .c3 {
      order: 1;
      background: yellow;
    }
  </style>
</head>
<body>
  <div class="parent">
    <div class="child c1"></div>
    <div class="child c2"></div>
    <div class="child c3"></div>
  </div>
</body>
</html>
